Real image type viewfinder

Details Real image type viewfinder Real image type viewfinder

1996-03-21

1998-03-10

Nguyen, Thong

Optical: systems and elements

Compound lens system

Telescope

359422, 359708, 396379, 396382, G02B 2300, G02B 2500

Patent

active

057267995

ABSTRACT:
A image type viewfinder is provided with, in the following order from the object side: an objective lens group, a condenser lens group which transmits the image of the object formed by the objective lens group towards an eyepiece lens group, an image erecting optical system that erects an inverted image, and, the eyepiece lens group. The objective lens group consists of a first negative lens group and a second positive lens group, located in this order from the object side wherein first negative lens group and second positive lens group forming a movable variable focal length lens group. The first negative lens group comprises a double-aspheric lens which satisfies the following relationships:

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